Life Cycle

Propagation

Stems

Leaves

Has smooth, hairless leaf blades, and upper leaf sheaths usually smooth and hairless, but the lower ones may be somewhat hairy; ligule (g) also membranous but usually a bit longer (2 - 3 mm), and there is a tuft of long hair on either side of the leaf-base (h) of the lower leaves; no auricles.

Roots and Underground Structures

Habitat

Both kinds of crab grass are common in southern Ontario but they also occur sporadically in northern and northwestern Ontario. Both occur in row crops and other fields, waste places, gardens and lawns.

Distinguishing Features

Before heading out, they are distinguished by their tapered leaf blades, their split sheaths with hairless margins (c), their membranous ligules (d, g) with no auricles, their more or less hairy lower leaf sheaths (b), and their either hairy or smooth blades. After heading out, the slender finger-like spikes are distinctive.

Resources

Bio Control Agents

The stem gall fly, Urophora cardui

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